Abrasive tool



Jan. 7, 1969 v. A. KO| ESH 3,420,007

ABRAS IVE TOOL Filed July 11, 1966 .8 F/GZ H63 United States Patent3,420,007 ABRASIVE TOOL Victor Anthony Kolesh, Holden, Mass., assignorto Wallace-Murray Corporation, a corporation of Delaware Filed July 11,1966, Ser. No. 564,369 US. Cl. 51-209 7 Claims Int. Cl. B24d 3/00ABSTRACT OF THE DISCLOSURE An abrasive tool comprising a coarse gage,open mesh woven wire screen disk providing a rigidly formed abrasivesurface area, with voids extending therethrough, and an abrasive coatingof scattered, hard, sharp-edged particles covering the face of thescreen wires including their sides extending into the voids, wherebyerosion of the abrasive surface area produces successively availableabrading surfaces, each consisting of a lower level of firmly attached,and not theretofore used, sharp-edged particles.

The present invention relates to improvements in abrasive articles, andmore particularly to a novel abrasive tool for high speed grinding andabrading operations.

It is a principal object of the invention to provide an abrasive tool ofnovel and improved construction which is fast cutting, durable and welladapted for operating efiiciently upon a substantially increased rangeof materials not readily acted upon by sanding and abrading devicesknown in the art.

It is a further object of the invention to provide a novel and improvedabrasive tool of the general character illustrated which willautomatically discharge from the abrading area any waste materialproduced by the abrading operation.

In accordance with the invention, there is provided an abrasive toolhaving as the base element thereof a coarse gage open mesh woven wirescreen providing an abrasive surface area with voids extending throughsaid base element and an abrasive coating of scattered hard, sharp edgedparticles covering the exposed face of each said wire, including theside portions extending into said voids, the arrangement being such thatas erosion of the abrading surface takes place including the breakingoff of particles and wearing down of the wire surface, a new abradingsurface is formed consisting of particles adhered to the rounded sidesof the wires which are unused. In this manner successively usable unusedgrit particles are made available at successively lower levels as theabrasive tool of the invention wears.

With the above and other objects in view as may hereinafter appear, theseveral features of the invention together with the advantages to heobtained thereby will be readily apparent to one skilled in the art fromthe following description taken in connection with the accompanyingdrawing, in which:

FIG. 1 is a view of one face of a wire mesh abrading wheel embodyingtherein the several features of the invention;

FIG. 2 is a fragmentary view on an enlarged scale of the coarse openmesh abrading wheel of FIG. 1 before any wear has taken place;

FIG. 3 is a fragmentary view similar to FIG. 2 showing the condition ofthe wheel after some wear has taken place;

FIG. 4 is a detail sectional view taken on a line 44 of FIG. 3; and

FIG. 5 is a detail sectional view taken on a line 5-5 of FIG. 3.

The abrasive wheel illustrated in, the drawing as em- 3,420,007 PatentedJan. 7, 1969 bodying in a preferred form the several features of theinvention is made up of a coarse open mesh wire to which is brazed agrit of small sharp edgeparticles of a very hard material such astungsten carbide. These particles are spread over the top and adjacentrounded side portions of the screen wires providing an abrading materialof substantial thickness. Under normal operating conditions the abrasivewheel will be driven at high speed. As wear takes place the particles ofthe top layer become worn or are broken off. The screen mesh, being ofsofter material, erodes exposing a new layer or fringe of particlesclinging to the rounded surfaces of the screen wires at a lower level.The particles are liberally scattered over the surface of the rapidlymoving wheel to insure a uniform, even cutting action of the wheel upona work surface as each successive level of particles is exposed bycontinued wear of the wheel. Waste material accumulated carbideparticles is automatically discharged through the interstices of therotating wheel thereby avoiding clogging of the cutting surface of thewheel and insuring a maximum efliciency of operation during the entirelife of the wheel.

The abrasive disc in the drawing comprises a heavy gage coarse mesh wirescreen 10, of which the voids provided by the interstices 12 are inexcess of the wire area, although this is not essential. The wire screen10 is fitted at one side thereof with a central annular flange or collar14 to be fitted to a suitable driving spindle, not shown. Acircumferential Wire support 16 is preferably attached to the under sideof the screen 10 to further support the outer peripheral area thereof,although it may be attached in the same plane or on the upper side ifthe wire screen is dished.

The upper face of the woven wire screen is covered with particles oftungsten carbide 18 crushed and graded for size. The particles arebrazed onto the wire surface with copper, nickel, or other suitablemetallic material acting as a flux. Simultaneously, the various wires inthe woven wire mesh are joined into a single mass. In the preferredenbodiment of the invention shown, a wire mesh of 6 x 6 per inch isused. The wire size is 16 gage and the grit is 20-30 or 30-40 mesh. Thewire is preferably double crimped, and the carbide chips are copperbrazed to the screen. While in the illustrated embodiment of theinvention a heavy gage open mesh wire which is self supporting isemployed, it will be understood that other grades of wire may besubstituted therefore including grades which are not self supporting andfor which suitable supporting structure may be required. Wire seize mayvary from No, 5 to No. 22, the wire mesh may vary from 1 x 1 to 16 x 16,and the grit size will be mesh, or coarser, but not finer than 100 meshdepending upon the requirements of the particular job. In no case shouldthe openings be closed completely. In the embodiment of the inventionshown, the wire gage and mesh are chosen to the particular job. In nocase should the openings be closed completely. In the embodiment of theinvention shown the wire gage and mesh are chosen to produce an abrasivewheel suitable for a wide variety of uses. The substantial voidsprovided by the wide mesh woven wire extending through the abradingsurface of the tool are of great importance to provide a means forclearing the cutting surfaces by the discharge of waste materialtherethrough.

The coarse mesh wire abrading wheel above described is normally made upfrom wire screening, the circular wire support 16 andcollar 14 beingsecured thereto, and thereafter only those surfaces required for cuttingare coated. The abrading wheels made up in this manner are primarilyintended to be used on power driven equipment at fairly high velocity,preferably in the order of 4,000 to 12,000 surface feet per minute. Itwill be understood that abrading tools in accordance with the inventionmay be made up in a variety of forms which will include grinding pads,sanding discs, abrasive drums, and combination sander-saws.

The abrading tool above described has certain unique qualities whichadapt the tool for the more efficient performance of many operationsheretofore considered impractical for normally available sanding andabrading equipment. Highly eflicient results may be obtained forexample, during operation upon materials which are of soft texture,gummy or dirty, or are heat sensitive, or which may be compositions ofone or more hard-to-sand materials, or which may contain harsh foreignmatter such as nails. Examples of such materials would include paintedwood and metal surfaces, rubber, plastic and other materials ofcomparable texture, and concrete surfaces whether wet or fully cured.Material is removed in the form of chips which are driven off by thecutting edges and forced outwardly through the interstices of the wiremesh. The removal of waste is further assisted by the flow of air, orother lubricant which may be present induced by the rapid movement ofthe wire mesh Wheel.

The invention having been described, What is claimed 1. An abrasive toolhaving, in combination, a base element comprising a rigid coarse gage,open mesh woven wire screen disk having its woven wires bonded togetherproviding a rigidly formed abrasive surface area with voids extendingthrough said base element, and an abrasive coating of scattered hard,sharp edged particles covering the face of each said wire exposed withinsaid surface area including the side portions extending into said voids,whereby erosion of the abrasive surface area produces successivelyavailable abrading surfaces each consisting of a lower level of firmlyattached and not theretofore used, sharp edged particles.

2. The combination of claim 1 in which the coating of particles and theWires of said woven screen are brazed together into a rigid unyieldingunit.

3. The combination of claim 2 in which the particles are tungstencarbide chips.

4. The combination of claim 1 in which the woven wire screen disc has acentrally attached hub, and an annular rim attached to the periphery ofsaid disc.

5. The combination of claim 1 in which the screen has a wire mesh ofabout 6 x 6 per inch and a wire size of 16 gauge and an abrasive grit of20-30 to 3040 mesh.

6. The combination of claim 1 in which the screen has a Wire mesh ofbetween 1 x 1 and 16 x 16, a wire size of between 5 gauge and 22 gaugeand an abrasive grit of 100 mesh or coarser.

7. A rotary abrasive disc having, in combination, with an annular hub, abase element comprising a disc shaped, coarse gage, open mesh woven wirescreen attached to said hub providing an abrasive surface area withvoids extending through said base element, and an abrasive coating ofscattered hard, sharp edged particles covering the face of each saidwire exposed within said abrasive surface area including the sideportions extending into said voids, and means brazing said particles andthe wires of said screen into a rigid self supporting unit, wherebyerosion of the abrasive surface area including the exposed top portionsof said wires and particles brazed thereto produces successivelyavailable abrading surfaces each consisting of a lower level of firmlyattached and not theretofore used, sharp edged particles.

References Cited UNlTED STATES PATENTS 2,376,254 5/1945 Humphrey 51-400X 2,562,587 7/1951 Swearingen 51-309 2,740,239 4/ 1956 Ball 51-4042,818,694 1/1958 Tocci-Guilbert 51404 2,838,890 6/1958 McIntyre 51-3953,150,470 9/1964 Barron .a 51400 LESTER M. SWINGLE, Primary Examiner.

D. G. KELLY, Assistant Examiner.

